-NRLF 


B  ^  am  sat 


, 

No.  1794 


DESCRIPTION 


OF  THE 


WIND  COMPONENT  INDICATOR 


MECHANICAL  FEATURES,  METHODS  OF  ASSEMBLING  AND 

DISMOUNTING,  AND  RULES  GOVERNING  ITS  CARE 

AND  PRESERVATION  IN  SERVICE 


{ONE  PLATE) 


JULY  15,  1906 
REVISED  MARCH  23,  1908 


WASHINGTON 

GOVERNMENT  PRINTING  OFFICE 

1917 


No.  1794 


DESCRIPTION 


OF  THE 


WIND  COMPONENT  INDICATOR 


MECHANICAL  FEATURES,  METHODS  OF  ASSEMBLING  AND 

DISMOUNTING,  AND  RULES  GOVERNING  ITS  CARE 

AND  PRESERVATION  IN  SERVICE 


{ONE  PLATE) 


1 1,  t.    O^A 


VI 


JULY  15,  1906 
REVISED  MARCH  23,  1903 


WASHINGTON 
GOVERNMENT  PRINTING  OFFICE 

1917 


\V1 


Wak  Department, 
Office  of  the  Chief  of  Ordnance, 

Washington,  May  23,  1912. 
This  manual  is  published  for  the  information  and  government  of  the  Regular 
Army  and  Organized  Militia  of  the  United  States. 
By  order  of  the  Secretary  of  War : 

Williaai  Ckoziek, 
Brigadier  General,  Chief  of  Ordnance. 

10048—17  (3) 


3G52r>l 


THE  WIND  COMPONENT  INDICATOR. 


DESCRIPTION. 

1.  The  wind  component  indicator  consists  of  a  dial  (2F).  for  read- 
ing- range  and  deflection  wind  components.  It  is  made  of  bronze,  and 
on  its  face  are  engraved  reference  numbers  for  range  and  deflection 
components.  The  lines  on  the  face  of  the  dial  are  alternately  heavy 
and  light;  the  heavy  lines  passing  at  right  angles  through  the  center 
of  the  dial  (2F)  are  the  axes  of  the  dial.  The  range  component  ref- 
erence numbers  are  engraved  along  the  vertical  axis,  and  the  deflection 
component  reference  numbers  are  engraved  along  the  horizontal  axis. 
Each  heavy  line  passes  through  a  reference  number,  the  value  of 
which  is  some  multiple  of  10.  Each  light  line  passes  through  a  refer- 
ence number  the  value  of  which  is  some  odd  multiple  of  5.  The 
smallest  reference  number  used  with  the  scale  is  0,  the  largest  100. 
As  shown  on  the  plate,  these  reference  numbers  read  from  0  on  the 
left  to  100  on  the  right,  and  from  0  at  the  bottom  to  100  at  the  top, 
with  50  in  the  center. 

2.  The  dial  is  intended  to  be  held  in  a  vertical  position  by  means  of 
the  bracket  (2S),  of  bronze,  which  is  fastened  to  the  back  of  the  dial 
in  such  manner  that  the  dial  itself  will  not  turn,  and  hence  the  figures 
on  it  will  always  be  right  side  up. 

3.  Around  the  dial  is  a  wind  azimuth  ring  (2D),  of  bronze,  gradu- 
ated and  numbered  clockwise  every  5  degrees,  and  movable  about  the 
dial;  the  dial  and  the  wind  azimuth  ring  are  secured  together  by  an 
undercut  seat  in  the  dial,  a  projecting  annular  ring  in  the  wind  azi- 
muth ring,  three  clamp  plates  (2T),  and  the  clamping  and  guide  plate 
(2K),  in  such  manner  that,  although  allowing  relative  angular  mo- 
tion between  the  parts,  they  can  not  be  dismounted  without  removing 
the  screws  holding  the  clamp  plates  and  the  clamping  and  guide 
pLate  to  the  dial.  At  the  bottom  of  the  dial  an  azimuth  pointer  (2M) 
is  attached.  By  moving  the  wind  azimuth  ring,  which  has  a  knurled 
edge  for  convenience  in  handling  and  setting,  to  any  required  degree 
as  indicated  on  the  dial  by  the  azimuth  pointer,  it  may  be  clam-ped 
securely  in  place  for  the  desired  setting  by  means  of  the  dial  clamp- 
ing screw  (2N). 

4.  Embracing  both  the  dial  and  the  wind  azimuth  ring  and  ro- 
tating about  an  axle  at  the  back  of  dial  is  the  target  arm  (2H),  of 


bronze,  beirl  fo  alicyr  it  to  pass  ove)-  the  dial  clamping  screw.  The 
azimuth  index  (2L)  is  screwed  to  one  end  of  the  target  arm  and  the 
target-arm  scale  (2J),  of  bronze,  to  the  other.  The  latter  is  secured 
to  the  center  of  the  dial  from  the  front  by  the  pivot  screw  (•2A). 
One  of  the  clamping  screws  (2P),  serves  to  clamp  the  end  of  the  tar- 
get arm,  to  which  azimuth  index  is  secured,  in  any  desired  position 
about  the  wind  azimuth  ring.  The  other  clamps  the  pointer  (2Q), 
of  forged  steel,  which  slides  through  a  islot  in  a  projecting  lug  near 
the  central  end  of  the  target-arm  scale.  By  relieving  the  clamping 
screw  the  pointer  may  be  set  for  any  velocity  of  wind  from  0  to  50 
miles  per  hour,  as  indicated  on  the  targ^-arm  scale. 

5.  All  exposed  surfaces  not  subject  to  sliding  friction  are  sand- 
blasted. Figures,  letters,  and  graduations  are  blackened.  The  place 
of  manufacture,  date,  serial  number,  and  initials  of  the  inspector 
are  engraved  on  the  face  of  the  dial. 

CARE   AND   USE. 

6.  The  instrunient  should  be  kept  clean  and  free  from  dust.  Sur- 
faces subject  to  sliding  friction  should  be  oiled  when  necessary  with 
clock  oil. 

7.  The  instrument  is  to  be  suspended  from  the  ceiling  of  the  chart 
room  immediately  over  the  plotting  board  and  facing  the  range  and 
deflection  boards,  so  that  the  operators  of  these  boards  can  readily  see 
the  range  and  deflection  components  without  leaving  their  stations. 
In  using  the  instrument,  the  operator  first  sets  the  pointer  to  the 
velocity  of  the  wind,  and  the  wind  azimuth  ring  to  the  azimuth  of  the 
wind  as  obtained  from  the  meterological  station.  He  then  keeps  the 
target  arm  set  to  the  azimuth  of  the  target,  as  indicated  by  the  gun 
arm  of  the  plotting  board,  moving  the  target  arm  as  the  target  moves. 
Should  the  wind  change  in  velocity  or  direction,  he  makes  the  neces- 
sary changes  in  the  position  of  the  pointer  or  the  wind  azimuth  ring. 
The  sharp  end  of  the  pointer,  extending  over  the  dial,  indicates  at 
once  the  proper  deflection  and  range  components. 

War  Department, 

Office  of  the  Chief  of  Ordnance, 

Washington,  May  23,  1912. 
July  15,  1906. 
Revised  March  23,  1908. 
Form  No.  1794. 
Ed.  Aug.  27-17—1,000. 

o 


furt 


10048- 


10048 — 17.     (Face  page  6.) 


.^•>^.C'  <'v  ..■'"^' 


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JAN16  1918 


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